1. Field of the Invention
The present invention relates to a vacuum cleaner, and more particularly to an automatic control method for controlling a travelling and cleaning operation of such a vacuum cleaner, which during an operator's designation for a cleaning region simultaneously with causing the cleaner to travel along the outline path of the cleaning region by using a remote controller, stores data for sectional distances of travelling paths of the outline path of the cleaning region and path directions, then divides the cleaning region into a plurality of cleaning blocks by using the data for the sectional distances and the path directions, thereafter, controls the cleaner to travel along the sequential cleaning blocks in order to clean the cleaning blocks simultaneously with overlapping a predetermined width of each cleaning block.
2. Description of the Prior Art
As shown in FIGS. 11 and 12, in which FIG. 11 is a block diagram showing a construction of a known vacuum cleaner, and FIG. 12 is a schematic plane view showing the construction of the cleaner of FIG. 11, the known cleaner comprises a travelling control circuit 31 for controlling the travelling and cleaning operation of the cleaner, a position discriminating circuit 32 for discriminating the present position of the cleaner represented in two-dimensional coordinates, that is, a x-coordinate and a y-coordinate, in every unit travelling distance. The known cleaner includes a manipulating part 33 for turning on/off the electric system of the cleaner, changing a travelling mode of the cleaner, determining a start position of the cleaning operation and adjusting photosensitivity of sensors, a remote transmitter 34 and a remote receiver 35 for carrying out a remote control for the cleaner, a reversible driving motor 38a and 38b for driving a front wheel 36 and a pair of rear wheels 37a and 37b, respectively. The front wheel 36 is disposed at a front portion of the cleaner but the rear wheels 37a and 37b are disposed at right and left sides of a rear portion of the cleaner, respectively. The known cleaner is also provided with a suction motor 40 for driving a pair of dust suction parts 39 disposed at both sides of a front portion of the cleaner.
In addition, the known vacuum cleaner is provided with a motor driving part 41 for driving the motors, a plurality of obstacle sensors 42 each for sensing an obstacle which may be in the travelling paths of the cleaner, calculating the distance between the cleaner and the obstacle in case of sensing an obstacle, then outputting an electric signal corresponding to the sensing of the obstacle to the control circuit 31, a pair of contact sensors 44 for outputting an electric signal corresponding to a state of contacting with the obstacle in the travelling paths of the cleaner to the control circuit 31 and a signal amplifier 53 for amplifying the electric signals applied from the sensors 42 and 44 thereto, then outputting the amplified signals to the control circuit 31.
On the other hand, the position discriminating circuit 32 is provided with a distance sensor 45 for outputting an electric signal corresponding to the travelling distance of the cleaner, for example, a pulse signal being directly proportional to revolutions of the front and rear wheels 36, 37a and 37b, to the control circuit 31, a direction sensor 46, for example, a gyrometer, for sensing a path directional change of the cleaner. While, the control circuit 31 provided with a central processing unit 47 (hereinafter, referred to simply as "the CPU") for controlling the control system of the cleaner, a plurality of input and output ports 48 by/from which the data signals are inputted and outputted, a ROM 49 and a RAM 50 for storing control programs and informing data therein, a clock 51 for generating a system clock and an interrupt controller 52 for performing an interrupt control routine.
The travelling operation synchronizing with the cleaning operation of the known cleaner will be described in detail in conjunction with FIGS. 13 and 14. FIG. 13 is a flowchart showing a process for controlling the known cleaner of FIG. 11, and FIG. 14 is a schematic view showing the trace of wheels of the known cleaner resulting from a travelling and cleaning operation by means of the process of FIG. 13.
As shown in FIG. 14, there is an obstacle X disposed at a center portion of the rectangular cleaning region which is to be cleaned by the cleaner of FIG. 11. Here, the user first manipulates the manipulating part 33 in order to select a learning travel mode, then remotely controls the cleaner by means of a remote controller in order to locate the cleaner at a start position S. Thereafter, a set button of the manipulating part 33 is manipulated in order to set the two-dimensional coordinates (xo and yo) of the start position S and a reference angle .THETA.o in the path direction of the cleaner.
Sequentially, the cleaner travels along the outer paths represented at the phantom line of FIG. 14 in accordance with a remote control by virtue of the remote control transmitter 34, thereby starting the learning travel step of the control process. At this time, the position discriminating circuit 32 determines the present position of the cleaner in the type of x and y coordinates and an angle .THETA. in the path direction, then outputs electric signals corresponding to the present position and the angle .THETA. to the CPU 47 wherein the present position and the angle .THETA. are stored in the RAM 50. Upon accomplishing the learning travel step of the cleaner 30, the CPU 47 divides the cleaning region by a unit distance, that is, a width "W" of the cleaner 30, parallel with the x-axis and the y axis of the two-dimensional reference system, thereby dividing the cleaning region into n cleaning blocks, then stores the n blocks on a memory map in the RAM 50.
Thereafter, the user locates the cleaner 30 at the start position S or at a position A near the start position S, then manipulates the manipulating part 33 in order to change the operational mode of the cleaner 30 from the learning travel mode into an unmanned travel mode. In result, the motor driving part 41 drives the wheel motors 38a and 38b under the control of the control circuit 31, thereby causing the cleaner 30 to travel along a first travelling path. At the same time, the suction motor 40 drives the dust suction part 39 in order to perform the cleaning operation.
Here, the cleaner 30 automatically and sequentially travels along a first column of the cleaning blocks which includes the position A. At this time, upon sequentially travelling along the first column, the CPU 47 stores the cleaning blocks, on which blocks the cleaner 30 has passed, simultaneously with erasing the number of said blocks, on which the cleaner 30 has passed, from the total number of the total blocks which have been stored in the RAM 50. Simultaneously with discriminating the present position of the cleaner 30 and the outline of the cleaning region by means of the position discriminating circuit 32, determining whether there is the obstacle X on the present travelling path of the cleaner 30 by means of the obstacle sensors 42, and changing the path direction, the CPU 47 controls the cleaner 30 in order to sequentially travel along the next column.
Upon sensing the obstacle X disposed at the F position, the CPU 47 changes the path direction of the cleaner 30 in order to allow the cleaner to travel along columns of the cleaning blocks which are not yet cleaned. At the same time, the CPU 47 stores in the RAM 50 the cleaning blocks, on which blocks the obstacle X is disposed, thereby making it impossible to clean said blocks, then controls the cleaner 30 to repeatedly travel, under a reciprocating motion, between the obstacle X and the outline of the cleaning region. Then, upon determining that the obstacle X is not sensed, the CPU 47 controls the cleaner 30 to simply travel along a straight column in order to reach a B position.
Upon reaching the B position, the obstacle sensor 42 and the position discriminating circuit 32 outputs respective signals to the CPU 47, said signals informing of a condition that there are several cleaning blocks which are not yet cleaned in the right side of the B position. In result, the CPU 47 stores the two-dimensional coordinates of the B position in the RAM 50, then controls the cleaner 30 to repeatedly travel, under the reciprocating motion, between the obstacle X and the outline of the cleaning region, thereby causing the cleaner to reach the C position. Thereafter, the cleaner 30 is controlled in order to return to the D position, then travels, in the same manner as above-described, along the remaining columns of the cleaning blocks which are to be cleaned thereby. In result, the cleaner 30 reaches the position G in order to stop the travelling and cleaning operation thereof.
However, in the above-mentioned method for automatically controlling the travelling and cleaning operation of the cleaner, the cleaning region after having been designated by performance of the learning travel step is divided by a plurality of x axis and y axis on the basis of an unit distance, that is, the width of the cleaner, into n regular square cleaning blocks. Thereafter, the blocks are stored on a memory map provided in a RAM of control circuit. In addition, upon storing the cleaning region in the RAM by storing the cleaning blocks in the same number of memory locations as that of the blocks, the CPU stores data for cleaning accomplishment of a cleaning block, on which block the cleaner is located, in the memory location of said cleaning block.
In result, the known method has disadvantage in that there have to be provided n memory locations corresponding to the n cleaning blocks, thereby causing the memory capacity to need to unnecessarily increase.
In addition, the number of the cleaning blocks increases in proportion to the area of the cleaning region, so that the known method has another disadvantage in that the cleaning region is obliged to be limited due to the limited memory capacity.
As described above, the longitudinal and lateral distances of the cleaning region are divided by the unit distance, thus, there may be a remaining region which remains out of the divided blocks, for example, the remaining region which remains out of the 13.times.13 cleaning blocks of FIG. 14, said remaining region being represented at the deviant lined portion. In result, the known method has another disadvantage in that the cleaner does not travel along the remaining region so that the region can not be cleaned.
Furthermore, the known method has another disadvantage in that the cleaner can not efficiently clean the boundary regions between respective blocks as the regions are out of the cleaning effect of the cleaner.